Pre- and post-harvest management to control Botrytis storage rot in New Zealand kiwifruit
M.A. Manning and R.M. Beresford.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Pre- and post-harvest management to control Botrytis storage rot in New Zealand kiwifruit
Storage rot (Botrytis cinerea)of ‘Hayward’ kiwifruit became aserious problem inNew Zealandduring the 1980s, costing theNZ$200m industry up to NZ$10m per year. Disease symptomsdevelop during 4-8 weeks storage at 0°C. A single rotting fruit in atray can cause the whole tray to soften prematurely. Control attemptswith pre-harvest fungicides led to resistance inB. cinereato dicarboximide and benzimidazole fungicides.B. cinereais onlyvisible in the orchard on flower petals, although it occurs on allplant surfaces, in understory weeds and in necrotic kiwifruitleaves. Infection occurs through the picking wound at harvest. Researchinto storage rot risk factors revealed a relationship betweenrot incidence and the incidence ofB. cinereaon discs of necrotickiwifruit leaf tissue sampled late in the growing season. From this,a predictive system has been developed that can identify high-riskorchards. The botrytis problem has largely been solved by vinemanagement that avoids dense leaf canopies and thereby avoidsnecrotic leaf tissue on whichB. cinereamultiplies. It was alsofound that the picking wound can be “cured” by storing fruit for48 hours at ambient temperature before cooling, which greatly reducesrot incidence. Incidence is also reduced by harvesting fruitwhen they are more mature (>6o Brix), as riper fruit are much lesssusceptible to botrytis than immature fruit. The botrytis storagerot problem has thus been avoided by a combination of pre-harvestorchard management and post-harvest handling practices,without the need for intervention with fungicides.